The first major development in the 2012 US presidential race was handed down by the US Supreme Court on June 28 which found the Affordable Care Act to be constitutional.

Did Obama receive a bump in the polls, or did the ruling galvanize voters toward Romney? And what about the betting market? (I explain the background to the betting market in this post on the 2008 election.)

Not earth shattering, but it does seem there was a little movement. The Iowa market saw Obama receive a bump from $55.40 to $57.20 – a legitimate increase taking Obama near the top of his range since the beginning of June. Romney, meanwhile, took a hit from $46 to $43.20.

The polls, however, were quieter, with only a small move in Obama’s direction. While noting the disparity between the markets and the polls, it may be worth pointing out that almost half of Americans either did not know what the Supreme Court had ruled on the ACA, or thought it had been struck down, according to a Pew Research Center poll.

But if we take the IEM for what it is – a probability – the move makes sense. The constitutional ruling did not change anything; it maintained the status quo.

So while the polls may not have moved much right now, the IEM move could indicate that the market viewed this as a crucial turning point. Maybe it’s not going to move the needle now, but it has set this election on a certain path that may be just a bit friendlier to Obama.